You can check the Dow Jones Industrial Average of you want one of the most up to date quotes on the price of your stock. The Wall Street Journal also carries stock prices daily as to what the price was when the stock market closed the previous day. There are also tons of special stock market watch sites that closely follow stock prices while the market is open. Most all major newspapers in the United States also carry stock prices not only in their printed editions, but up to the minute prices on their web sites as well. There are also several news services on cable and satellite TV that exclusively track stocks all day long and have a running banner on the bottom of the screen that tracks not only Wal-Mart stock, but everything that is listed on the Dow Jones Exchange as well as NASDAQ.
If that's not enough for you, visit Wal-Mart's web site at walmart.com, they have a section of their web site dedicated to tracking their stock. There are several online stock brokers where you can buy Wal-Mart stock and in turn, track their stock to the minute as the price changes on the DJ Industrial Average.
If you want to check on your Wal-Mart stock, you have a ton of options to choose from and if you have a computer with internet access, you have even more.